Saneyasu Takaoki, Fujita Shoichi, Kitashiro Ayana, Fukuzo Satoshi, Honda Kazuhisa, Kamisoyama Hiroshi
Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan.
Graduate School of Agricultural Science, Kobe University, Kobe, 657-8501, Japan.
Neurosci Lett. 2018 Mar 23;670:48-52. doi: 10.1016/j.neulet.2018.01.032. Epub 2018 Jan 31.
The central anorexigenic mechanism seems to be similar in mammals and chicks, because the appetite-suppressive action of a number of peptide hormones is similar in both species. Accumulating evidence in mammals has revealed that hypothalamic Akt-mediated signaling factors (for instance, mTOR and FOXO1) are significantly involved in the regulation of food intake. However, the role of hypothalamic Akt in feeding regulation is yet to be determined in chickens. In this study, we showed that pAkt (Thr308)/Akt, pFOXO1/FOXO1, and pS6 levels were significantly increased in the hypothalami of chicks refed 1 h after a 24 h-fast in correlation to increases in the plasma concentrations of insulin, one of the activators of the Akt-mediated signaling pathways. In addition, central administration of insulin increased the phosphorylation of Akt, FOXO1, and S6 in chicken hypothalami. Furthermore, intracerebroventricular injections of both phosphoinositide 3-kinase inhibitor LY294002 and mTOR inhibitor rapamyacin enhanced the food intake of chicks. These findings suggest that hypothalamic Akt-mediated signaling pathways contribute to the regulation of food intake in chicks.
哺乳动物和雏鸡的中枢性厌食机制似乎相似，因为许多肽类激素的食欲抑制作用在这两个物种中是相似的。哺乳动物中越来越多的证据表明，下丘脑Akt介导的信号因子（例如，mTOR和FOXO1）显著参与食物摄入的调节。然而，下丘脑Akt在鸡的采食调节中的作用尚待确定。在本研究中，我们发现，禁食24小时后再喂食1小时的雏鸡，其下丘脑的pAkt（Thr308）/Akt、pFOXO1/FOXO1和pS6水平显著升高，这与Akt介导的信号通路激活剂之一胰岛素的血浆浓度升高相关。此外，向鸡下丘脑中央注射胰岛素可增加Akt、FOXO1和S6的磷酸化。此外，脑室内注射磷酸肌醇3激酶抑制剂LY294002和mTOR抑制剂雷帕霉素均可增加雏鸡的采食量。这些发现表明，下丘脑Akt介导的信号通路有助于调节雏鸡的食物摄入。
